Redox reactions, or oxidation-reduction reactions, have a number of similarities to acid-base reactions. Fundamentally, redox reactions are a family of reactions that are concerned with the transfer of electrons between species. Like acid-base reactions, redox reactions are a matched set — you don't have an oxidation reaction without a reduction reaction happening at the same time. Oxidation refers to the loss of electrons, while reduction refers to the gain of electrons. The word oxidation originally implied reaction with oxygen to form an oxide, since (di)oxygen was historically the first recognized oxidizing agent. Later the meaning was generalized to include all processes involving loss of electrons.
The word reduction originally referred to the loss in weight on heating a metallic ore such as a metal oxide to extract the metal. Lavoisier showed that this loss of weight was due to the loss of oxygen as a gas. Later it was realized that the metal atom gains elections in this process, and the meaning of reduction was generalized to include all processes involving gain of electrons. The electroche mis t John Bockris has used the words electronation and deelectronation to describe reduction and oxidation processes respectively when they occur at electiodes. These words are analogous to protonation and deprotonation, but they have not been widely adopted by chemists.
The primary process of reducing ore to produce metals is discussed in the article on Smelting. Oxidation is used in a wide variety of industries such as in the production of cleaning products and oxidizing ammonia to produce nitric acid, which is used in most fertilizers. Redox reactions are the foundation of electrochemical cells. The process of electroplatin呂 uses redox reactions to coat objects with a thin layer of a material, as in chrome-pla ted auto motive parts, silver plating cutlery, and gold-plated jewellery. The production of compact discs depends on a redox reaction, which coats the disc with a thin layer of metal film. Biological energy is frequently stoted and released by means of redox reactions. Photosynthesis involves the reduction of carbon dioxide into sugars and the oxidation of water into molecular oxygen. The reverse reaction, respiration, oxidizes sugars to produce carbon dioxide and water. As intermediate steps, the reduced carbon compounds are used to reduce nicotinamide adenine dinucleotide (NAD*), which then contributes to the creation of a proton gradient, which drives the synthesis of adenosine triphosphate (ATP) and is maintained by the reduction of oxygen.
In animal cells, mitochondria perform similar functions. Free radical reactions are redox reactions that occur as a part of homeostasis and killing microorganisms, where an electron detaches from a molecule and then reattaches almost instantaneously. Free radicals are a part of redox molecules and can become harmful to the human body if they do not re a ttach to the redox molecule or an ant ioxidant. Unsatisfied free radicals can spur the mutation of cells they encounter and are thus causes of cancer. The term redox state is often used to describe the balance of NAD+/NADH and NADP7NADPH in a biological system such as a cell or organ. The redox state is reflected in the balance of several sets of metabolites (e.g., lactate and pyruvate, betahydroxybutyrate and acetoacetate), whose interconversion is dependent on these tatios. An abnormal redox state can develop in a variety of deleterious situations, such as hypoxia, shock, and sepsis. Redox signalling involves the control of cellular processes by redox processes. Redox proteins and their genes must be co-located for redox regulation according to the CoRR hypothesis for the function of DNA in mitochondria and chloroplasts.
The book has been designed to cover the syllabus of this subject. Care has been taken to make the treatment of the subject simple and accessible to the average students.

Preface vii

1. Cyclic Voltammetry Experimental Method • Voltammetry • Electroanalytical Method • Karl Fischer Reaction • Coulometres • Theory of Operation • Amperometry • Galvanic Anode • Dropping Mercury Electrode • Hanging Mercury Drop Electrode • Working Electrode • Reference Electrode • Auxiliary Electrode • Randles-Sevcik Equation 1

2. Electrochemistry 16th to 18th Century Developments • Background and Dawn of Electrochemistry • Principles • Electrochemical Cells • Battery • Dry Cell • Homemade Cells 33

3. Corrosion Galvanic Corrosion • Methods of Protection from Corrosion • Types • Problems • Iron Corrosion • Techniques 76

4. Balancing Redox Reactions Redox Reactions and Electrode Processes • Titrimetric Analysis (Redox Reactions) • Balancing Redox Reactions Using the Half Reaction Met hod • Reduction or Oxidation • Balancing Redox Reactions in Acid Solution 119

5. Metabolism The Metabolic Map as a Set of Dots and Lines • The ATP Cycle • NMR as a Metabolic Probe • Metabolic Pathways are Compartmentalized within Cells • Special Focus • Human Biochemistry • Riboflavin and the Flavin Coenzymes • A Deeper Look—Vitamin B6 • Vitamin B12: Cyanocobalamin • Vitamin B12: Cyanocobalamin • Lipoic Acid • Folic Acid • The Vitamin A Group 164

6. Chemical Analysis by Redox Titration Bioinorganic Systems • Composition of Living Organisms • Types of Inorganic Elements in Biology 209

7. The Electronic Structure of Surfaces Measuring the Electronic Structure of Surfaces with Angle- Resolved Photoemission • The Photoe mission Process • Band Mapping: 2d Bands and 3d Bands 221

Bibliograhy 251

Index 255

Owen Parker is Professor of Chemistry &Biochemistry. His specialization is in Homogeneous catalysis (C-H and C-halogen bond activation,oxidation). Luminescent materials, Conducting polymers, Metal coordination chemistry, Development of highly fluorinated ligands,Bioinorganic chemistry and Metals in medicine and disinfection science. Most of his research projects are interdisciplinaryin nature.

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